Install Adobe Acrobat Reader DC

I keep trying to install Acrobat Reader DC. It says "Install Adobe Acrobat Reader DC wants to make changes. Type your password to allow this. It has a Username: Rachelle Snell and then asks for a Password:????? Below that it has a cancel button or OK button.

I don't have a password. I try every password I've ever used for anything and no luck.

What do I do? Please HELP!

Thank you.